1. Field of the Invention
The present invention relates to the solar energy development automation field, and in particular to a sunlight collection device and a method for tracking sunlight.
2. The Related Arts
Sunlight is inexhaustible supply green energy, people have been constantly trying to utilize solar energy, such as the well-known solar water heater and the photovoltaic power generation. In recent years, there rises a way of utilizing directly sunlight to light up, namely, collecting sunlight effectively in outdoor and transmitting it to indoor through the optical fiber. It is great significance to the places where the safety is stringently required, such as ammunition depots, oil tanks, mines and other flammable and explosive places as well as the construction where cannot directly receive the sunlight. The core idea of such techniques is to utilize the collecting lens or the condenser mirror, focusing the sunlight on to the fiber, transmitting the sunlight to the place where requires the light through the optical fiber. This lighting technique saves energy and photoelectric isolation, which is a very safe way of lighting. The key of this technique is that highly precisely and automatically tracking the sun, ensuring that the sunlight is gathered on the light-receiving face of the optical fiber. The methods for tracking sun proposed by the current patent are divided into two main categories: one is to control the daylighting illumination device according to the rule of the Earth running around the sun; the other is to tracking the sun by utilizing the photoelectric sensor.
The sunlight collection device which utilizes the photoelectric sensor to track sunlight is to utilize multiple photoelectric sensors to consist of a sensor array, because of the angle between the sunlight and each photoelectric sensor is different, the sunlight signal intensities detected by the respective photoelectric sensors are different. Therefore, the position of the sun can be calculated according to the difference of the signal intensity, thereby, turning on the motor to make the sunlight collection device rotate toward the sun direction. After several probing, calculating, moving, it can make the sunlight collection device achieved better alignment accuracy. However, the mechanical structure of the traditional sunlight collection device is to make a sunlight tracking system, then fixing the collecting lens and the optical fiber on the sunlight tracking system, namely, the sunlight tracking system is separated with the collecting lens and the optical fiber. This separate assembly requires maintaining high mechanical precision during fixing, to ensure the light spot which is condensed by the collecting lens irradiated onto the light-receiving of the optical fiber. If the mechanical alignment is offset due to wind, shaking and other reasons when the system is running, there will occur a phenomenon that although the sensor array precisely locating to sunlight and the light spot which is condensed by the collecting lens deviates the light-receiving of the optical fiber. And the prior art cannot repair itself when this phenomenon occurs, thus it will reduce the lighting collection, thereby reducing the utilization rate of light.